Shock absorbing device



Nov. 24, 1936.

w. NOBLE SHOCK ABsoRBING DEVICE Filed Feb. 2s, 1954 I l i ZI/arrenZoZje.

Patented Nov. 24, 1936 gi) STATES atti,

Vi' T HQE 2,061,806 SHOCK ABsoneiNG DEVICE Massachusetts ApplicationFebruary 28, 1934Serial No. 713,334

12 Claims.

My invention relates to shock absorbing devices, and more particularlyto shock absorbing devices for preventing the transmission of thevibrations of rock drilling motors to the operator or drill runner.Numerous attempts have been made to provide shock absorbing connectionsbetween hammer motors and the handles therefor, such as spring cushions,air cushions and the like, but because of the guided relation ordinarilyprovided in at least some planes and involving` direct metal to metalsurface contacts between motor elements and handle or handle mountingelements, successful elimination Aof the transmission of vibra-- tionhas not been fully attained.

It is an objecty of the present inventionto pro# vide an improved'resilient supporting means between a drill motor handle and the drillmotor proper, and', by the use of supporting means of very smallmassrand the elimination of all metal to metal contact, to eliminate thetransmission oi substantial vibration.

It is a further object of the invention to provide, in a drilling motorhaving a resiliently mounted handle, and between the throttle valve onthe drill motor proper and the primary operating means for the throttlevalve arranged on the handle, aA

iiexible connection which shall not be alected by the relative movementsbetween the drilling motor and the handle.

Another object of my invention is to provide an improved air cushiontype of resilient connection between a handle and the drilling motor towhich the same is connected.

Still another object of the invention is to provide an improved annularpneumatic cushion adapted for arrangement either in transverse or inlongitudinal planes with respect to the drilling motor, for the purposeof absorbing the vibrations of the latter and relieving the drill runnerof iatigue and shock. Other objects of the invention will hereafterappear.

In the accompanying drawing, in which I have shown for purposes ofillustration one illustrative embodiment of the invention, together witha modification,

Fig. 1 is a view, partially in central vertical section and partially inelevation, of a drilling motor in which an illustrative embodiment ofthe invention is incorporated.r

Fig. 2 is a transverse section on a plane corresponding to the planev ofthe line 2 2 of Fig. 1.

Fig. 3 is a fragmentary view showing the upper end of a drill and thehandle therefor, showing a modied form of construction.

Referring now to the drawing, it will be observed that a rock drillingmotor, generally designated i, has a hammer piston 2 reciprocable in itscylinder 3 and adapted to actuate a drill steel il. Fluid distributionto the motor is effected under the control of any suitable valvemechanism enclosed within a valve chest 5, and iluid is supplied to thevalve chest from any suitable supply line i3 under the control of athrottle mechanism 'l which I shall shortly describe.

lb As is well known, hammer motors of the character illustrated cannotbe made free from vibration, and for the purpose of preventing thetransmission of the vibrations of the motor to the handle mechanism v3 Ihave provided improved vibration absorbing and shock eliminating meansgenerally designated lll. To the rear end of the motor there is secured,in the form shown in Fig. 1,

circular Vportions I9 are suitably held together by 30 bolts 2U and nuts2 l and form together a circular member having an annular internalconcave rimlike seat portion 23.

Between the seats, I3 and 23, there is mounted a suitable pneumaticcushion member, herein in the shape of a small inner tire-tube, havingwalls of rubber or the like of suitable thickness to permit themaintenance of a substantial pressure therein, the precise pressure` tobe maintained varying with the weight of the drill, the intensity 40 ofthe vibration, etc. This member, which is designated 25, may be placedin position between the approximately properly positioned members l2 andI9 and then inflated, or may be seated upon the seat I3, then inflated,and the two handle parts may be assembled around the member 25, and heldtogether by the bolt and nut means described. In either case, through asuitable inflating device 26 a suitable pressure will be provided in thedoughnut-like member 25, and its pressure and the thickness of the wallsof this member will be minimized, as far as possible, to meet` theconditions which must be overcome, so that the total mass of theconnection may be kept as small as possible.

A suitable operating lever 28 is pivotally connected at 23 to one of thesemicircular members iii, and extends in general in the direction of oneof the handle portions l5. A spring 36 extends between the lever it andthe handle portion l5, and a Bowden wire 3l extends from a point 32 uponthe lever to an approximately balanced throttle valve 33 which is of thedouble seat type. It will be evident that gripping of the handle elementi5 and the lever lill to cause approach of the lever 23 to the handlewill pull upon the Bowden wire and upon the throttle valve. Release ofthe lever 28 will allow the spring 30 to cause the lever to push uponthe Bowden wire and close the throttle valve. Because of the length ofthe Bowden wire and the presence of its sheath 34, suitably positionedby an elbow-like portion 35 integral with one of the parts I9 and byengagement with a closure element Sil for the throttle valve chamber,positive valve actuation can be effected without the transmission ofvibration through the operating connection or disturbance of valveadjustment due to vibration of the parts.

In Fig. 3, the disposition of the annular air cushions is shown inlongitudinal planes, and two are used at opposite sides of the axis ofthe drill motor for balance. In this form the member ll' is providedwith a pair of rearwardly extending earlike portions, di), M, eachhaving a peripheral concave seat portion d2. The handle structure Sincludes a pair of circular elements i3 and 44 having internal concaverim-like seats 45, surrounding and facing the concave seats :12.Separate pneumatic cushion elements of doughnutlike or inner tubetire-like form, respectively numbered lll and ll, surround the ears Eland 4I respectively. Appropriate inflating connections, as at 43, areprovided for these elements. The mode of operation for this element willbe very clear, for the action can be compared in a measure with thetires of an automobile in the shock absorbing function. Obviously thereis a difference, however, in the specific mode of operation.

It will be evident that a single annulus arranged in the axial plane ofthe motor would also function, provided dimensions and pressures areproperly selected.

In both forms, it will be observed that there is a balanced support forthe drilling motor by the handle. In both forms it will be evident thatthe transmission of vibrations from the motor to the handle will belargely eliminated. In both forms it will be evident that the mass ofthe connecting means between the handle and the drilling motor is verysmall. In both cases, it will be evident that metal to metal contactbetween the parts of the handle and the drill is eliminated, under anynormal working conditions. While the throttle control is not shown inFig. 3, it will be evident that it might be the same as that in Fig. lor might be of a hydraulic type if preferred, and that the throttlecontrol is possible from the handle, notwithstanding the flexiblemounting, and is capable of that graduated fineness which is frequentlynecessary in the operation of spotting or other special conditions.

While there is in this application specifically described one form whichthe invention may assume, in practice, together with a modification, itwill be understood that these forms are shown for purposes ofillustration and that the invention may be modified and embodied invarious other forms without departing from its spirit or the scope ofthe appended claims.

What I claim and desire to secure by Letters Patent is:

l. In combination, in a percussive` tool, an impact motor, a supportinghandle therefor, shock absorbing means between said handle and saidimpact motor including a pneumatic cushion of annular tire-like form,and supporting means on said handle and motor respectively for securingsaid annular cushion in position therebetween, one supporting meansprojecting within the open center of said annular cushion and saidsupporting means having concentric surfaces engaging the inner and outersurfaces of said annular cushion.

2. In a drilling apparatus, in combination, a drilling motor, a handle,said motor and handle providing oppositely facing concave rim-likeseats, and pneumatic annular cushion means of tire-like `form supportedby said seats and spacing said motor and handle.

3. In a drilling apparatus, in combination, a drilling motor, a handleresiliently and movably mounted with respect to said motor, a throttlevalve for said motor and mounted on the latter, and a connection betweensaid handle and throttle valve for operating the latter from the handleincluding an operating member mounted on said handle and a flexibleoperating connection between said operating member and said valve.

fl. In a drilling apparatus, in combination, a drilling motor having anexternal rim-like seat, an annular tire-like cushion member mounted onsaid seat, and a handle having an oppositely facing, circular internalseat engaging and surrounding said cushion member in spaced relation tothe first mentioned seat.

5. In a drilling apparatus, in combination, a drilling motor having atthe rear end thereof at least one element providing a circumferentialexternal concave rim-like seat disposed generally in planes extendingaxially of the motor, circular pneumatic cushion means of tire-like formsurrounding said seat, and a handle having oppositely-facing internalrim-like seat means surrounding and engaging said cushion means.

6. In a drilling apparatus, in combination, a drilling motor having atopposite sides of its axis a pair of members providing concave annularexternal rim-like seats, a handle having elements providing a pair ofconcave annular internal rim-like. seats in the same planes extendinglongitudinally of the motor as said first mentioned seats, and anannular pneumatic cushion of tirelike form between each pair ofcooperating seats afforded by said member and said handle and seated onsaid seats.

7. In combination, in a percussive tool, an impact motor, a manualsupporting handle therefor, a shock absorbing cushion between said motorand handle including an annular pneumatic yieldable means of tire-likeform, and supporting means on said handle and motor respectively forsecuring said annular pneumatic means in position-therebetween, onesupporting means projecting within the open center of said yieldablemeans and said supporting means having concentric surfaces engaging theinner and outer surfaces of said annular means.

8. In combination, in a percussive tool, an impact motor, a manualsupporting handle therefor, a shock absorbing cushion between said motorand handle including an inflated resilient annular pressure fluidreceptacle of tire-like form, and.

supporting means on said handle and motor respectively for securing saidannular receptacle in position therebetween, one supporting meansprojecting within the open center of said annular receptacle and saidsupporting means having concentric surfaceslfor engaging the inner andouter surfaces of said annular receptacle.

9. In a drilling apparatus, in combination, a drilling motor having anexternal seat, an an-V nular pneumatic cushion member mounted thereon,the inner portion of the exterior periphery of said cushion memberengaging said seat, and a handle having an oppositely facing, circularinternal seat engaging and surrounding said cushion member in spacedrelation to the rst mentioned seat, the outer portion of the exteriorperiphery of said cushion member engaging said oppositely facing seat.

10. In a drilling apparatus, in combination, a drilling motor having atthe rear end thereof at least one element providing a circumferentialexternal concave rim-like seat disposed generally in planes extendingaxially of the motor,`

circular pneumatic cushion means of tire-like form surrounding andseated on said seat, and a handle having oppositely-facing internalrimlike seat means surrounding said cushion means and on which thelatter is seated.

1l. In combination, in a percussive tool, an impact motor, a manualsupporting handle therefor, shock absorbing means between said handleand motor for preventing metal toV metal contact therebetween includingvan annular low pressure air shock absorbing cushion of tire-like form,and. supporting means on said handle and motor respectively for'securingsaid annular cushion in position therebetween, one supporting meanspro-- jecting within the open center of said annular cushion and saidsupporting means having concentric surfaces engaging the inner and outersurfaces of said annular cushion.

l2. In combination, in a percussive tool, an impact motor, a manualsupporting handle therefor, a pneumatic shock absorbing cushion betweensaid motor and handle and forming the sole connection between said motorand handle, said cushion including an inflated resilient receptacle ofannular tire-like forma-nd supporting means on said handle and motorrespectively for securing said annular receptacle in positiontherebetween, one supporting means projecting within the open center ofsaid annular receptacle and said supporting means having concentricsurfaces engaging the inner and outer surfaces of said annularreceptacle.

WARREN NOBLE.

